How to hane an income throught facebook?

Tweet

Facebook is a socoal networking site's that is most populer today. Besides as away to make friends, it turns out facebook could also be a means to bring together ideas throught cyberspace. So many people who say that throught facebook as well we can do business online. And allready many people who said get substantial revenue throught facebook. I do not understan it! So, how do earn money online throught facebook? Please give me feedback!